Multicylinder fuel injection pump



Oct. 26, 1937. M. HURs'T Er Al.

MLTICYLINDER FUEL INJECTION PUMP `Filed Nov. 7, 195e 2 Sheets-Sheet l l ffy.;

Ct- 26, 193,7- M. HURsTy E'r AL MULTICYLINDER'FUEL INJECTION PUMP Filed Nov. 7, 1936 2` Sheets-Sheet 2 J-A I I 2 5a Patented Oct. 26, 19.37

UNITED f STATES Y 2,097,413 MULTICYLIN'DER FUEL INJECTION PUMP Max Hurst, Stuttgart, and Otto Beck, Winterbach, near Schorndorf, Germany, assignors to Robert Bosch Germany Aktiengesellschaft, Stuttgart,

Application November '1, 1936, Serial No. 109,784 In Germany November 26, 1935,*-

5 Claims. (Cl. 103-41) This invention relates to an injection pump for internal combustion engines having several separate pumps arranged in a casing, the pumping members of which are each driven from a driv- 5 ing element in the common pump casing by means of 'a transmission member guided in the casing, and can be angularly turned by a common member serving for controlling the amount of fuel injected, while at least one oblique controlling l enge in each separate pump allows a variable' amount of the fuel pumped in excess by the piston to flow back.

The invention has for its object to enable a single pump to be easily changed in the case of' l'damage to the pumping element, and renders possible the insertion in the pump casing of a complete reserve single pump even by an unskilled Workman, While avoiding difcult adjustments and setting relatively to the other separate pumps.

According to this invention each separate pump, is formed as a closed unit independently of the .other separate pumps, can be inserted from above into a common pump .easing ready for working in such a Way that it generally assumes,

without requiring further subsequent adjust-l ment, the correct position relative to its stroke transmission member arranged in the pump casing and to the common fuel amount controlling 30 member that is also mounted in the pump casing.

An example of construction of the inventionl is shown in the accompanying drawings, in

which@- Figure 1 is an elevation, partly in longitudinal section, of a four-cylinder pump.

Figure 2 is a cross section through the pump and a pump insert member.

Figure 3 is a side elevation of a pump insert member capable of being fitted in the pump casing.

Figure 4 is a horizontal cross section through the flange of the insert member on the line IV-IV of Figure 3.

Figure 5 is an elevation partly in isectionthese plungers being guided in the casing I, and

driving the separate pumps. Each of the pumps is arranged separately from the others in anl insert member 5, which. in its middle part is formed a's a ilange 5a, whichA closes the pump casing I at the top and is detachably connected to the casing. In the interior of the flange part a chamber 6 is provided, serving as a suetion and return flow chamber, and from the flange part cylindrical longitudinally bored extensions 5b and 5c respectively extend upwards and downwards which receive the pumping element. This consists of the pump piston 1 and its cylinder bush 8, around Whose part which freely projects into the bored out extension 5b the controlling sleeve 9, provided at the top with teeth, is rotatable. In the lower part of the extension 5b a plunger sleeve III is guided, which bears on its respective plunger 4. In order that on the suction stroke the piston, plunger sleeve, and plunger shall follow' the cam, the piston is pressed by a spring Il on the bottom of the plunger sleeve I0, and this latter on the plunger.

The other end of the spring is supported in the insert member. The plunger sleeve is s ecured in the insertbody by a sprung-in ring I2, so that it is not pressed out of the insert member when the latter is not fitted in position.

In the upper extension 5'0 of the insert member'the spring-pressed pressure valve I3 is arranged in a valve carrier I3a, which is pressed on the cylinder bush 8 in known manner by the v threaded nipple I4, whereby this bush is pressed against a shoulder in the flange part 5a. A sleeve I6, which secures the threaded nipple against slackening is drawn over the threaded nipple I4 to which the pressure pipe I5 is connected. y The ange 5a of each insert member secured by pump' is connected to the common lfuel feed pipe I8 of all the pumps.

Fory the uniform alteration of the delivery amount of all the separate pumps a toothed rackbar I8 is provided, which is mounted so as to be longitudinally movable in the casing, and is in engagement with toothed segments 20 (Fig. 2). Each .of the toothed segments 20 carries a pin 2l, which -is rotatably mountedl in the pump casing I. vOn the upper face of the-toothed segment 20 a driving memberZIla is provided, which engages in the lower of two cross slots running' at-right angles to eachother of an intermediate' coupling piece 24 (Fig. 5). A sprung-in ring 25 which lies in an annular groove in the lower slotted part of the Vcoupling piece 24 and also engages in grooves in theouter ilanks of the driving member secures the piece 24 to the segment 20, when one is inserted over the other, by embracing the driving member.

A driving member 22a of a lengthv of shaft 22 projects into the upper slot of each coupling piece 24, the shaft being revolubly mounted in the insert member 5, and carrying a toothed segment 23 clamped in it which meshes with the toothed controlling sleeve 9 of the pump. The pins 2|, as Well as the shafts 22, aresecured by set-screws 26 against being drawn out when changing an insert pump member.

In removing an insert pump member from the casing, the coupling of the shafts 22 to the intermediate coupling piece 24 is undone. 'Ihe toothed segment 23 remains however in engagement with the teeth on the controlling sleeve 8 i Fig. 3), also the segment 20 remains in engagement with the rackbar I9.

In inserting a substitute insert member in the casing oi the injection pump, it is simply necessary to take care that the shaft 2| is-correctly coupled to the intermediate piece '24, so that the oblique controlling edge of the pump piston -of the newly inserted single pump is given the same adjustment or setting relative to the return flow opening as that of the other pump pistons. Aslthe toothed segment of a reserve pump insert member is already correctly adjusted relative to the controlling bush, it requiresfas a rule, with .this simple arrangement, no subsequent adjustment. By dividing the easily coupled shafts, and by inserting a pair of toothed segments, the toothed controlling parts remain in engagement with one another in changing the separate pumps, so that the possibility of changing the separate pumps is ensured without altering the adjustment of the fuel delivery amount or the -beginning of the injection.

An opening 21, which is closed by a protective cover 28 open at the bottom is employed for Ventilating the pump casing.

We declare that what we claim is:

1. A multicylindenfuel injection pump comprising in combination a common casing, a plurality .of individual pump cylinders each having suction and return passages, a pump plunger housed as a unit within each cylinder, a sleeve extension on each cylinder, a rotatable plunger controlling element mounted ineach sleeve extension, a spring controlled plunger mounted in each extension, a plurality of countershafts each mounted as a unit with a cylinder, gearing between each countershaft and its rotatable plunger controlling element, means to detachably secure said cylinders to said casing, a iiange on each cylinder setting the position of adjustment of Aeach cylinder axially of the cylinder, la. plurality of countershafts'carried by.- said casing, a common control element in said casing,- gearing between said ountershafts and said .common control eler'nen't, detachable coupling means between 2.'-A multicylinder fuel injection pump com- .prising in combination a common casing, a plurality of pump cylinders each having Vsuction `and .return-passages, a pump plunger housed as al unit`='within each` cylinder, means to rotate each pump plunger to adjust its eiIective stroke', a. plurality of countershafts each mounted as a unit with a cylinder,v gearing between each counter-V shaft and its plunger rotating means, means to detachably secure each cylinder on saidcommon casing, a control element in said casing. a plurality of countershafts permanently housed in said casing, gearing .between said countershafts and said control element, coupling means between each countershaft in said casing and each countershaft mounted in said detachable cylinders, and a common driving element in said casing for the said pump plungers.

3. A multicylinder fuel injection pump comprising in combination a common casing, a plurality of pump cylinders each having suction and return passages, a pump plunger housed as a unit Within each cylinder, means to rotate each pump plunger to adjust its effective stroke, a plurality of countershafts each mounted as a A unit withy a cylinder, gearing between each countershaft and its plunger rotating means, means l to detachably secure each cylinder on said common casing, a control element in said casing, a

plurality of countershafts permanently housed in said casing, gearing between said countershafts and said control element, a'dog coupling disc between each countershaft in said casing and each countershaft mounted in said detachable cylinders, and a common driving element in said casing'for the said pump plungers.

4. A multicylinder fuel injection pump comprising in combination a common casing, a plurality of pump cylinders each having suction and return passages, a spring-pressed pump plunger housed as a unit within each cylinder, a plunger guide cup mounted in each cylinder, stop means for retaining each plungermcup in its cylinder, means to rotate each pump plunger to adjust its eiective stroke, a plurality of countershafts each mounted as a unit with a cylinder, gearing between each countershaft and its plunger rotating means, means to detachablyscure each cylinder on said common casing, a control elevment in said casing, a plurality of countershafts permanently housed in said casing, gearing between said countershafts and said control element, a loose dog coupling disc detachably connected to each countershaft in said casing and each countershaft mounted in said detachable cylinders, and a-common driving element in said casing for the said pump cylinders.

5. A multicylinder fuel injection pump comprising in combination a common casing, a plurality of pump cylinders each having suction and return passages, a pump plunger housed as a unit within each cylinder, means to rotate each pump plunger to adjust its effective stroke, a plurality of countershafts each mounted as a unit with a cylinder, gearing between each countershaft and its plunger rotating means, means to detachably secure each cylinder on said common casing, a control element in said casing,a plurality of countershafts permanently housed in said casing, gearing between said countershafts and said 

